库尔勒香梨光合特性的初步研究

[目的]了解库尔勒香梨光合生理特性及其相关变化规律.[方法]利用Li- 6400光合作用测定系统测定库尔勒香梨两种树形的光合特征参数,通过试验测得光合色素含量以及比叶重,进行分析探讨.[结果]两种树形的光合色素含量存在差异,疏散分层形树的Chla含量极显著大于开心形,Chla+ Chlb值在25.88～38.96 mg/cm2,而两种树形之间的比叶重均值相差不大；开心形和疏散分层形的光补偿点(LCP)分别是28.75、33.22 μmol/(m2·s),在光强为1 090 μmol/( m2·s)时开心形树达到光饱和点,对应最大净光合速率值为18.61 μmol/(m2·s),低于疏散分层形的饱和光强1 150 μmol/( m2·s)；开心形和疏散分层形的CO2浓度补偿点分别是63.55和57.04 μmol/mol,两种树形的羧化效率(CE)分别为0.039 5、0.036 6.在CO2浓度达到1 135 μmol/mol时,开心形的净光合速率达到最大值,为29.34 μmol/( m2·s),疏散分层形CO2饱和点(CSP)为1 165 μmol/mol.[结论]疏散分层形树对强光以及对CO2的利用率较高.

Preliminary Study of Photosynthetic Characteristics on Korla Fragrant Pear

【Objective】To study the photosynthesis characteristics and variation law of Korla Fragrant Pear.【Methods】Measure the photosynthesis parameters of two type tree shape of Korla Fragrant Pear by Li-6400 and the photosynthetic pigments content and specific leaf weight by experiment methods,discussing the data results.【Result】The results showed that the photosynthetic pigments showed significant differences.The delayed-open central leader shape in content of chlorophyll was significantly higher than that of the open center shape.The total content of chlorophyll changed from 25.88 mg/cm2 to 38.96 mg/cm2,but there was no difference in specific leaf weight of different tree shape;The light compensation point of the open center shape and delayed-open central leader shape were 28.75 μmol/m2·sand 33.22 μmol/m2·s.The net photosynthetic rate of open center shape was 13.36 μmol/m2·s when reaching its light saturation point 109 0 μmol/m2·s,which was lower than that of delayed-open central leader shape 1 150 μmol/m2·s;The CO2 compensation concentration point of open center shape and delayed-open central leader shape were 63.55 μmol/mol and 57.04 μmol/mol,the carboxylation efficiency of both shapes were 0.039 5 and 0.036 6.The net photosynthetic rate of open center shape reached its peak value 29.34 μmol/m2·s when CO2 concentration reached 1 135 μmol/m2·s.The CO2 saturation concentration of delayed-open central leader shape was 1 165 μmol/m2·s.【Conclusion】The delayed-open central leader shape of light and carboxylation use efficiency was higher than that of the open center shape.